front-end

Short definition from Wiktionary

Noun

1. 1
   Alternative form of front end.
2. 2
   That part of a hardware or software system that is conceptually closest to the user; the user interface.
3. 3
   Used other than figuratively or idiomatically: see front, end.

Adjective

1. 1
   Relating to the front end or user interface of a hardware or software system.
2. 2
   Of a financial transaction, paid or charged first.